1. Field of the Invention
The present invention relates to roof shingles, and in particular, to an interlocking roof shingle and a roofing system comprising a plurality of interlocking roof shingles.
2. Brief Description of the Prior Art
Because of their exposure to the elements, roofs are provided with weather proofing to prevent damage to the interior structure. On residential buildings in particular, the roof is provided with a predetermined pitch to allow moisture to run off the roof. Secured to the roof are shingles which are overlapped in accordance with the pitch of the roof to direct moisture and/or water off of the roof. A variety of materials are used as roofing shingles, such as, metal, wood, and petroleum based materials. The most widely used shingles are made of asphalt because of their durability and ease of installation.
A primary reason for using roof shingles is to protect the interior of the building from water intrusion caused by rain and/or snow. High winds often damage these roof shingles by lifting and bending the shingle, thereby increasing the likelihood of water intrusion. A common technique in applying roof shingles is to overlap adjacent shingles such that the areas where the nails or staples fasten the shingle to the roof overlap. This technique for applying roof shingles to the roof allows the water to run downwardly from the roof top without penetrating the areas containing the fasteners. Typically, a roof will also contain a water barrier layer beneath the roof shingles, such as, tar paper to protect the roof so that the water does not enter the interior of the building.
Several roofing material products are available in the market place, such as tar shingles which traditionally are used, slate, shingle, simulated wood products, and metal sheeting. Some of these products, such as tar shingles, have advantages over some of the other roofing materials currently used in the market place in that they are relatively inexpensive and perform relatively well. Even though the other types of roofing material may be more expensive, an advantage of the more expensive roofing materials is that these types of roofing materials allow a different look to be applied to the roof of a building; but yet may suffer from poor performance since these types of roofing materials contain many seams and connection sites which usually are not weather-tight and which roofing materials are difficult to maintain. Recently, there has been an increased interest in metal roofing products in that they tend to have a desirable appearance, are durable, and provide high weather-tight performance compared to non-metal roofing products.
In a typical roofing installation, the roof shingles are installed beginning at the lowest point of the roof and extending out over the bottom edge of the roof. The shingles are mounted in rows with the side edge of each shingle proximate the adjacent shingle. The shingles in a row are not connected together nor are they overlapping each other, and fasteners, generally nails are used to attach the shingles to the roof. Subsequent rows of shingles generally are arranged to overlap the shingles in the immediately lower rows, but since there are no interconnections between the shingles, placement and spacing of each shingle relative to each other are left to the installer.
In order to facilitate installation and variation in climate conditions, asphalt shingles are widely used because of their flexibility. However, this characteristic, i.e. flexibility, in general, allows the asphalt shingle to be easily damaged by extreme winds which bend and tear the asphalt shingle. This condition is particularly troublesome in colder climates where the asphalt shingles tend to become brittle and eventually break. Other rigid type materials used in roof shingles, such as shake, clay, and metal generally are susceptible to damage from extreme temperatures and the natural expansion and contraction of these types of building materials.
A desirable aspect of shingle and slate roofing, irrespective of high cost and maintenance, is that the different colors or hues of the material can be composed on a roof to create a very appealing appearance, which is the result of a process called blending. Blending is the intentional placement of individual or groups of shingles having different colors or hues next to each other to create the desired aesthetic effect; such as, a weather-worn roof, a moss-laden roof, or simply a variety of different colors.
There is, therefore, a need in the art to provide a roof shingle which combines the advantages of prior art shingles while avoiding the disadvantages thereof.
There is still a further need in the art to provide a roof shingle and roofing system which greatly increases the structural integrity and durability of the roofing system even in high winds to prevent water intrusion.
There is a further need in to the art to provide an interlocking shingle which fits tightly with an adjacent shingle to prevent any rain or moisture from entering beneath the shingles to increase the life of the roofing system.